The present invention concerns a steam pressure reducing and conditioning valve.
FIG. 3 illustrates a first embodiment steam pressure reducing and conditioning valve (hereinafter xe2x80x9cconditioning valvexe2x80x9d) 130 wherein hot and high pressure steam S inflowing from a first port 131 is desuperheated and depressurized by passing through a pressure reducing section 132 having scattered small holes 132a, and transformed into a rapid annular flow steam S1. The steam S1 is discharged from a second port 133 as desuperheated and depressurized steam S2 by supplying the rapid annular flow vapor S1 with subcooled water mist W in a body 136.
As shown in FIG. 4, the subcooled water mist W is injected from a nozzle 134, into a moisture jet section 135, and the jet pattern of this subcooled water mist W is conical. The subcooled water mist W injected from nozzle 134 collides with the steam S1, to cool down the steam S1.
Referring again to FIG. 3, when the subcooled water mist W injected from the nozzle 134 comes into contact with the pressure reducing section 132 in a hot state, the pressure reducing section 132 may crack and break due to an extreme temperature change. To prevent the cracking, the subcooled water mist W from the nozzle 134 should not come into contact with the pressure reducing section 132.
Consequently, in the prior art, the nozzle 134 is disposed remote from the pressure reducing section 132 so that the subcooled water mist W injected from the nozzle 134 will not come into contact with the pressure reducing section 132, thereby increasing the size of the body 136 and necessarily resulting in enlargement of the whole valve.
The superheated steam S is cooled by colliding the rapid annular flowing steam S1 with the subcooled water mist W, and further dispersing the droplets (mist) of subcooled water W.
However, when the nozzle 134 is disposed remote from the pressure reducing section 132 for the aforementioned reason, it is difficult to disperse (subdivide) the subcooled water as the velocity of the annular flowing steam decreases with the distance from the pressure reducing section 132.